Method and system for using dynamic boundaries to manage the progression of ride vehicles that have rider control inputs

ABSTRACT

A method for controlling vehicle progression along a ride path of an amusement park ride. The method includes receiving inputs from a passenger of a vehicle on the ride path and processing the received inputs to determine a vehicle state change. The method includes determining a present or predicted vehicle state and comparing the present or predicted vehicle state with constraints defined by a dynamic boundary associated with the vehicle. The method includes issuing vehicle control commands to a drive assembly to implement the vehicle state change if it complies with the constraints. The dynamic boundary is moved logically along the ride path at a nominal to define a set of boundaries for movement of the vehicle along the ride path. The vehicle state change may be a change that causes the vehicle to travel at a speed differing from the dynamic boundary while remaining within the dynamic boundary.

REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No.13/936,694, which was filed on Jul. 8, 2013 and is hereby incorporatedby reference in its entirety.

BACKGROUND

1. Field of the Description

The present invention relates, in general, to methods and systems forcontrolling or managing the overall progression of passenger vehiclesthrough an amusement park ride, and, more particularly, to methods andsystems that use dynamic boundaries to define allowable rider inputsthat modify vehicle speed and, in some cases, direction of movementalong the intended ride path.

2. Relevant Background

Amusement park rides or simply “rides” have been around for more than acentury and have been used to entertain millions of visitors toamusement park rides, theme parks, carnivals, and fairs, typically bymoving one or more riders in each vehicle along a track. For example,roller coasters move passengers rapidly along a track while some themerides may include slow or show portions as well as fast or thrillportions. Park operators are continually searching for new ride designsto enhance the passenger's experience and to encourage repeated use of aride, i.e., looking for something that makes the ride different orunique enough each time that a park visitor will take a ride many times.

Many rides allow the passenger or rider some control of their vehiclealong the ride path. Many rides exist where the passenger vehicle isconfigured to allow a rider to provide input to rotate their vehicle toface any direction. However, the rider has no control over speed or thevehicle path as the vehicles are, for example, connected to a chainpulled along a track to move the vehicles along a ride path. In otherwords, no mechanism is provided for the rider to influence the movementof the vehicle along the ride path.

In other rides, the passenger can more fully control the vehicle's speedand direction along the ride path or track, e.g., go kart-type or bumpercar-type rides. However, there is no mechanism for the ride operator tomanage the vehicle spacing to ensure either throughput or show spacing.As a result, these rides do not meet the park operator's demands forrides with high and known throughput and for rides designed to placevehicles proximate to show elements at predefined show times such aswhen animatronics or display systems are operated to entertain passingpassengers in the vehicles. In contrast to these rider-controlled rides,typical amusement park rides move passenger vehicles through a showspace at programmed speeds and with programmed vehicle spacing. Thespeeds are used to provide a desired throughput and also to provide adesired show experience for the passengers, and the spacing is used toensure passenger safety by avoiding collisions and also to provide adesired show experience (e.g., some level of individual experience foreach vehicle in portions of the ride).

SUMMARY

There is a need and desire for rides that are designed and operated toprovide a degree of passenger or rider control over their vehicle thatallows the riders to affect their individual ride experience. With thisin mind, a ride (and method of controlling or operating such a ride) istaught that manages vehicle progression along a ride path or along apath defined by a track to provide known vehicle throughputs, safespacing of vehicles, and also provides control within certain portionsof the ride path such as in the load/unload station and in show spaces.

Further, though, the ride is adapted to use dynamic boundaries orenvelopes for each vehicle within which the vehicle's rider may provideinput to affect their ride experience by controlling movement within thedynamic boundary or envelope. Briefly, the ride includes a controllerthat controls movement and location of each vehicle such that it remainswithin a dynamic boundary, and the controller moves the dynamic boundary(which defines gross movement of the vehicle) along the ride path in thedirection of travel for the ride.

The dynamic boundary is configurable in some embodiments in that it maychange its size and/or shape along the ride path, e.g., the dynamicboundary may be 30 feet long in one section of the ride (with a 5 to 15foot long vehicle, for example) and then shrink to only be the length ofthe vehicle plus a safety or vehicle spacing distance (to avoidcollisions) in a show space or in the station. The rider may provideinput to speed up their vehicle, and the controller may allow thisacceleration within the dynamic boundary until the vehicle reaches (orapproaches) the leading or front edge of the dynamic boundary.Alternatively, the rider may provide input to slow their vehicle down toa speed that is slower than the speed of the dynamic boundary movement,and this may be allowed by the controller until it is determined thatthe vehicle is at or near the trailing or rear edge of the dynamicboundary. At this point, the controller may override the rider input andforce the vehicle to go at least the dynamic boundary speed to staywithin the confines of the dynamic boundary.

The amusement park ride and its control system are adapted to allowriders/passengers of vehicles to provide input (such as through a riderinput device/assembly such as foot pedals, a joystick, a touch pad orscreen, or other user input) to control their vehicle to modify theprogression of their vehicle along the ride path in a significant andinteresting way (e.g., control speed and/or direction of travel and notjust provide rotation/spinning). The ride is controlled with acontroller or control system so that ride throughput can be guaranteedto meet a design capacity for the ride such as by monitoring movement ofdynamic boundaries along the ride path and one or more vehicles withinsuch dynamic boundaries.

Using dynamic boundaries, which can be dynamically modified in sizeand/or shape, can allow the controller to manage movement of the ridevehicles in show portions and in unload/load areas of the ride path(e.g., within a station) such as by reducing the boundaries of thedynamic boundary to approximately the size and shape of the vehicle(with some safety distance provided to avoid collision in someapplications). The monitoring of movement of the dynamic boundariesprovides the attraction designers the flexibility to allow rider controlof the vehicles in some portions of the ride path while forcing thevehicles to arrive at a specific time and/or with specific spacing inother portions (such as show portions). The riders may control vehiclespeed and position within the dynamic boundaries without compromisingthe overall operation of the ride. The dynamic boundary method ofmanaging vehicle progress applies to nearly any ride with individual(not interconnected chains) vehicles that are allowed to move through aspace such as dark rides, free ranging vehicles (FRVs), boat rides, andso on.

More particularly, a method is taught for controlling vehicleprogression along a ride path of an amusement park ride. The methodincludes receiving inputs from input devices (e.g., a joystick, a brake,an accelerator, and so on) operable by a passenger of a vehicle on theride path. The method also includes processing the received inputs todetermine a vehicle state change and predicting a new vehicle state(e.g., from input from one or more sensors on the vehicle or along theride path). Then, the method includes comparing the predicted vehiclestate with a set of constraints defined by a dynamic boundary associatedwith the vehicle. Further, the method includes, based on the comparingstep and the vehicle state change, issuing vehicle control commands to adrive assembly of the vehicle to implement the vehicle state change,whereby the vehicle complies with the set of constraints.

In some embodiments of the method, the dynamic boundary (e.g., a logicalconstruct) moves (or is moved by a control program) along the ride pathat a nominal speed during operating of the amusement park ride, and thedynamic boundary defines a set of boundaries for the vehicle. In suchembodiments, the vehicle state change may be a change in the vehiclespeed and the issuing of the vehicle control commands causes the vehicleto travel at a speed differing from the nominal speed of the dynamicboundary, but the speed of the vehicle may be governed to force thevehicle to remain within the set of boundaries (e.g., slow down whenapproaching the front edge of the dynamic boundary).

The set of boundaries may define a dynamic boundary length as measuredbetween a leading end of the dynamic boundary and a trailing end of thedynamic boundary. Then, the length may be greater than a length of thevehicle at least for portions of the ride path. In some applications,the length of the dynamic boundary is modified from a first length in afirst portion of the ride path to a second length greater than the firstlength during a second portion of the ride path (e.g., to facilitatesafe path crossings or to provide more control in stations or in showsections of the ride path the dynamic boundaries may be shrunk to limitfree movement of the vehicle).

Likewise, the set of boundaries may define a dynamic boundary width thatmay be varied along the ride path, such that an amount of transversemovement of the vehicle is controlled to direct the vehicle throughopenings in obstructions. Further, the dynamic boundary may be split ata first location along the ride path into first and second dynamicboundaries and then later merged into a single dynamic boundary at asecond location along the ride path. In such cases, the vehicle statechange is processed to select the first or second dynamic boundary forconstraining progression of the vehicle along the ride path.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic drawing of a ride or ride system operating tomanage passenger vehicle progression along a direction of travel usingdynamic boundaries;

FIG. 2 shows the ride or ride system of FIG. 1 at a second time in whichvehicles have been moved within the dynamic boundaries (which themselvesare moving at some rate(s) of speed in the direction of travel);

FIG. 3 provides a graph illustrating an allowable vehicle speed rangewithin a dynamic boundary of FIGS. 1 and 2;

FIGS. 4A and 4B shows a portion of a ride using dynamic boundaries tomanage vehicle progression at a first time (or first operating state)and then at a later, second time (or operating state) to showprogression of a chain (or train) of dynamic boundaries along a ridepath with concurrent movement (X-Y directional movement in this example)of a vehicle within a dynamic boundary;

FIG. 5 illustrates a portion of a ride similar to that shown in FIGS.1-4B but further showing a ride path with an obstacle and splitting of adynamic boundary into two to provide two differing ride paths around theobstacle for boundary-constrained vehicles;

FIG. 6 illustrates a portion of a ride similar to those found in FIGS.1-5 or a length of a ride path of such a ride that is operated by acontroller (not shown) to reduce the size (e.g., length) of dynamicboundaries along the direction of travel (or over operating time) tofurther constrain the vehicles to a set of precise, planned movements(e.g., to limit or even eliminate freedom of movement of the vehiclesuch as for use near a show element or in a station);

FIG. 7 illustrates a portion of a ride similar to that shown in FIGS.1-6 that is operated by a controller to change the definition of adynamic boundary along the length of the track or ride path to force avehicle to travel through a restriction such as a door or gate (e.g.,reduce the width of the dynamic boundary to reduce travel transverse tothe direction of travel at the restriction or opening in anobstruction);

FIG. 8 shows a portion of a ride similar to that shown in FIGS. 1-7 witha path crossing and use of dynamic boundaries to safely manage progressof vehicles through the crossover point or intersection of thetrack/ride path;

FIG. 9 illustrates a functional block diagram of a ride or ride systemadapted for and operating to provide dynamic boundary-based control overvehicle progression along a ride path;

FIG. 10 illustrates a functional block diagram of a ride system withcomponents/features of the diagram of FIG. 9 adapted for vehicle-basedmanagement of the vehicle progression using dynamic boundaries; and

FIG. 11 illustrates a functional block diagram of a ride system withcomponents/features of the diagram of FIG. 9 adapted for off-board (oroff-vehicle) management of the vehicle progression through the rideusing dynamic boundaries.

DETAILED DESCRIPTION

The present description is directed toward methods and systems formanaging progression of vehicles along a ride path (which may beassociated with a track) for passenger vehicles configured for riderinput to control at least speed of the vehicle. Briefly, the ride orride system may be thought of as including a computer controlled vehicle(or a plurality of such vehicles) and a rider input device in thevehicle. A controller or control assembly is provided to achieve thecomputer-based control over the vehicle to manage progression of thevehicle along a ride path. The controller acts, such as by executingsoftware in the form of a control program or module, to define a dynamicboundary for the vehicle, and the dynamic boundary (or control envelope)defines a moving range of allowable vehicle positions along the ride orplanned path. In other words, the dynamic boundary may have a dynamicouter boundary (changes in size and/or shape along the ride path) movedover time along the ride path during operation of the ride, and thevehicle is controlled to remain within the boundaries (or inner space ofthe dynamic boundary) throughout the ride.

The controller further acts to respond to rider inputs from the inputdevice to change the position of the vehicle within the allowable rangeof vehicle positions, e.g., to allow the vehicle to move at differingspeeds than the dynamic boundary along the ride path, based on a presentlocation or position of the vehicle within the dynamic boundary. Therider input may be ignored if the vehicle is already in a rear mostposition within the dynamic boundary and the rider inputs decelerationcommands such that the controller forces the vehicle to move at theprogression rate of the dynamic boundary along the ride path, wherebycollision with a trailing vehicle in the next dynamic boundary isavoided. In another example, the rider may provide input to move thevehicle to or toward the front of the dynamic boundary, and thecontroller may allow such movement if the vehicle is not yet at thefront or leading edge of the dynamic boundary (e.g., the vehicle travelsfaster than the rate of travel of the dynamic boundary along the ridepath).

The inventors understood that typical spacing in rides between ridevehicles is much larger than the spacing needed to protect the vehiclesagainst collisions. With this in mind, the rides described along withtheir controllers are designed to take advantage of this extra space byallowing riders (or the controller) to change vehicle speed and move thevehicle forward or back within an allowable range of positions as thatrange moves along the ride path, e.g., the dynamic boundary in which thevehicle is positioned and allowed to move travels along the ride path ata controller set rate (which may be constant or may be varied by thecontroller along the ride path).

By way of analogy, consider a subway train with one person locked ineach car. The person may move about the car he is in but cannot leavethe confines or space defined by the walls or boundaries of the car asthe train and its cars move along a track. In this analogy, each car ofthe train represents a dynamic boundary while the person moving withinthe car represents a ride vehicle that can be operated or moved by arider/passenger. The space between cars may represent a protection zoneused to avoid collisions between the vehicles (e.g., 1 to 3 or more feetoften is all that is used).

By moving the subway train along a track, it is guaranteed that acertain number of people will be moved from Point A to Point B along thetrack path within a specified time by setting the train (and, therefore,car) speed and on a schedule. Likewise, a “train” of dynamic boundariesmay be moved along a ride path (which may be associated with a trackguiding the vehicles) to cause several vehicles to move from a loadportion of a station through a ride portion of the ride path and back toan unload portion of the station. As the train moves along the track,each person in each car can move freely within the car (forward andback, left and right, up and down) so that they sometimes move fasterthan the car and sometimes move slower than the car (and sometimes atthe speed of the car). Likewise, a simple ride system may be configuredsuch that a single vehicle is constrained to a single dynamic boundary,and a plurality or train of such dynamic boundaries is moved along aride path associated with a track supporting the vehicles at a nominal(e.g., substantially constant) speed. The passengers or riders may befree to drive their vehicles left or right along the width of thetrack/path and to change speeds. However, the dynamic boundary is usedto define the range of travel with its boundaries, and the dynamicboundary continues to move along the ride path. Hence, even though riderinput makes the vehicle responsive to the rider, each vehicle iscontrolled to prevent a vehicle from catching up to a leading car (asthe forward boundary of the dynamic boundary cannot be crossed) or fromcompletely stopping (as the rear boundary of the dynamic boundary cannotbe crossed by the vehicle). In this manner, the ride system isinteractive and entertaining and, at the same time, adapted to minimizethe risk of vehicles bumping into each other while concurrentlyincreasing the overall ride capacity by limiting or setting the maximumtravel time around the track or along the ride path.

Using dynamic boundaries for controlling vehicle progression allowsseveral other vehicle control options. The rider (or controller) mayprovide input to change speeds to dodge or hit obstacles. In a freeranging vehicle (FRV), the rider may provide input to explore showspaces by moving more to the left or right or slowing to see more of ashow/display or interact with gaming features. The vehicles may also beadapted to respond to off-board effects such as to be repositionedwithin the space defined by the dynamic boundary boundaries or to beaccelerated or decelerated relative to the dynamic boundary travel ratealong the ride path.

The controller (and its executed control program/module) may act tochange the size and/or speed of the dynamic boundaries at differentpoints along the ride path. The dynamic boundaries may be reduced insize (such as to moving points or to a space approximating the exteriorsize and shape of the vehicle itself) for vehicles entering or exiting astation. For a given dynamic boundary speed or travel rate, reducing theextent of the dynamic boundary may cause or be associated with anincrease in the size of the protection spacing between dynamicboundaries. This allows vehicle spacing to be guaranteed in areas wheretighter vehicle management is desirable such as at path crossings.Further, a ride designer may elect to change a size of the dynamicboundaries to guarantee vehicles arrive at a location at a specific timeor to ensure vehicle spacing for proper engagement with show elements.For unconstrained vehicles (such as FRVs), dynamic boundaries can beextended in three dimensions to allow for lateral and vertical vehiclecontrol by the rider and/or the controller within the dynamic boundaryas well as control in the nominal direction of travel.

Several approaches may be used to implement the dynamic boundaries witha control program executed by a controller (e.g., a computer system usedto control movements of vehicles in a ride system). In a first approach,the dynamic boundaries are software constructs defined and managed by acentral control system. Based on the defined dynamic boundaries,accurate knowledge of the vehicle position, and rider inputs, thecentral control system manages movement of the vehicle within thedynamic boundary and along the ride path. This may involve directlycontrolling the vehicle or by adjusting permitted range of movements ofthe vehicle. In a second approach, much of the responsibility forcontrol is moved to the vehicle such as with each being equipped with anonboard controller. In this approach, each dynamic boundary isimplemented as an integral part of the vehicle motion profile. In athird approach, the dynamic boundary is defined based on the position ofthe vehicle ahead to provide an anti-collision system as the vehiclesprogress along a ride path. Implementing dynamic boundaries provides arelatively straight forward and inexpensive method for managing progressof vehicles in a ride system, especially one utilizing vehiclescontrolled by a smart system (e.g., a computer controlled motion withaccurate position monitoring for each vehicle of the ride system).

The figures show how the concept of dynamic boundaries or vehicle motionenvelopes may safely manage movement of a set of vehicles along adefined ride path of an amusement park ride. FIG. 1 is a schematicdrawing of a portion of a ride or ride system 100 operating to managepassenger vehicle progression along a direction of travel using dynamicboundaries. In this relatively simple implementation, the ride 100 isshown to include three passenger vehicles 120, 122, 124 that aresupported upon and limited to travel along an elongate track 110. Thevehicles 120, 122, 124 may take numerous forms to practice the system100 such as wheeled or bogied vehicles or watercraft with onboard or offboard propulsion mechanisms that set the direction of travel 115 alongthe track 110 and the rate of travel or speed of each vehicle 120, 122,124. The vehicles 120, 122, 124 may include input devices for allowingthe rider(s) to provide input to affect the speed or other operation ofthe vehicles 120, 122, 124 along the track 110.

While not shown, an off board and/or onboard controller (or controlsystem) is used in system 100 (as discussed below) to respond to theuser input (or to control input from a ride program) to determinemovements 121, 123, 125 of the vehicles 120, 122, 124 including thespeed of the vehicles relative to the direction of travel 115 on thetrack 110. Particularly, each of the vehicles 120, 122, 124 iscontrolled by a controller that virtually positions or encases each ofthe vehicles 120, 122, 124 in a vehicle dynamic boundary 130, 134, 136,respectively, as shown in FIG. 1. During operation of the ride system100, the control of vehicle progression along track 110 is managed suchthat the dynamic boundaries 130, 134, 136 do not overlap and such thatthe vehicles 122, 124, 126 must remain within the boundaries defined fora corresponding one of the dynamic boundaries 130, 134, 136.

In some embodiments of the ride system 100, the dynamic boundaries 130,134, 136 may abut at adjacent ends or, as shown, a protection zone ordynamic boundary spacing 131, 135 with a length, L_(PZ), is providedbetween a leading and trailing pair of dynamic boundaries 130, 134, 136(e.g., a distance such as a few inches up to several feet). Moretypically, though, the stopping distance for a vehicle 120, 122, 124 atany point in a ride 100 (plus a cushion or safety factor) defines theprotection zone length, L_(PZ), and this defines a minimum dynamicboundary size (e.g., dynamic boundary length is length of the vehicleplus protection zone, L_(PZ)). Hence, the protection zone, 131, 135 insome cases (such as where dynamic boundaries abut each other) may beconsidered a part of the dynamic boundary (e.g., zone 131 is in dynamicboundary 130 and zone 135 is in dynamic boundary 134).

A nominal vehicle spacing, L_(NVS), may be defined for a ride system 100by combining a dynamic boundary length, L_(CB), with the length, L_(PZ),of the protection zone, 131, 135. Again, this may be set for the entireride along the track 110 or it may vary at differing points or locationsalong the track 110, e.g., allow larger (i.e., longer in the ride 100example) dynamic boundaries in some portions of the ride such as thrillsections and smaller dynamic boundaries in other portions such as inshow portions or in the station to facilitate loading and unloading ofthe vehicles. The nominal vehicle spacing length, L_(NVS), is measuredfrom trailing or second end 141 of a dynamic boundary 130 (trailingdynamic boundary in the pair) to a trailing or second end 142 of theadjacent (or leading) dynamic boundary 134. In contrast, the dynamicboundary length, L_(CB), is measured from a first or leading edge/end144 of a dynamic boundary 134 to a second or trailing edge/end 142 asshown in FIG. 1. In some embodiments, the width, W_(CB), of the dynamicboundary 134 may be varied along the track 110 or ride path, but in theride system 100 where the vehicles 120, 122, 124 are bound to the track110, the width, W_(CB), remains constant (e.g., is about the width of avehicle) as the vehicles only travel along the direction of travel 115(i.e., in the X direction) and not transverse to the direction of travel115 (i.e., in the Y direction) as is the case with many embodiments ofthe invention.

According to a unique aspect of ride system 100, the dynamic boundaries130, 134, 136 are used by a controller of the system 100 to controllocations and movements (e.g., progression) of the vehicles 120, 122,124 along the ride path associated with the track 110. Moreparticularly, the ride system 100 is operated or controlled such thatthe dynamic boundaries 130, 134, 136 along with the protection zones131, 135 progress along the ride path in the direction of travel at amanaged rate (which may be constant or be varied along the ride path bya controller). The vehicles 120, 122, 124, in contrast, can speed up orslow down (as indicated with arrows 121, 123, 125) as the dynamicboundaries 130, 134, 136 move at the dynamic boundary travel rate alongthe ride path of the track 110. In this way, the vehicles 120, 122, 124may occupy any position within their assigned or corresponding dynamicboundary 130, 134, 136.

FIG. 1 may be thought of as showing all the vehicles 120, 122, 124 in adefault vehicle position at the rear of the dynamic boundary (e.g.,against or proximate to a trailing edge 141, 142 of the dynamic boundarysuch as dynamic boundaries 130, 134). The vehicle 120, 122, 124 then iscontrolled by a controller of the ride system 100 to force it to travelin the direction of travel 115 at a rate matching that of the dynamicboundary 130, 134, 136 along the ride path (e.g., forced to remainwithin the boundaries of the dynamic boundary which is itself moving).The “default” position, though, may be any other position within thedynamic boundary 130, 134, 136.

Further, FIG. 1 is useful for showing that when a vehicle is at arearmost location it is controlled such that it cannot further slow downand any input to that effect such as braking would be ignored oroverruled by the controller (or its software programs). If no input isreceived from the rider, the vehicle 120, 122, 124 is moved along withits progressing/moving dynamic boundary. If the rider provides input toaccelerate to a speed faster than the dynamic boundary's speed orprogress rate along the direction of travel 115, the vehicle 120, 122,124 may move, as shown with arrows 121, 123, 125, forward within thedynamic boundary 130, 134, 136 toward the first or leading edge orboundary of such dynamic boundary 130, 134, 136.

This freedom of inner dynamic boundary space movement is shown in FIG.2. The vehicle 120 may be operated by its rider to brake or may beoperated with no rider input. Such braking results in the vehicle 120moving 121 in the direction of travel 115 along the ride path defined bytrack 110 at the rate or speed of the dynamic boundary 130. The vehicle122 is being operated by a rider to accelerate or move faster than itscontaining dynamic boundary 134 to move as shown with arrow 123 awayfrom the second or trailing edge/boundary 142 toward the first orleading edge/boundary. The vehicle 124 is being operated differently,being operated based on rider input (such as braking or releasing theaccelerator) to travel at a rate slower than the dynamic boundary oreven negative at a speed or rate opposite the direction of travel 115 asshown with arrow 125 indicating the vehicle 124 is moving within itsdynamic boundary 136 toward the trailing dynamic boundary 134 and itscontained/restrained vehicle 122. The vehicle speed may range widely andeven include negative speeds in the sense the vehicle is not moving inthe direction of travel along the ride path. The vehicle, though, muststay within its dynamic boundary such that the controller forces thevehicle to move at the dynamic boundary travel rate when the vehicle isat the rear most location within the dynamic boundary and when thevehicle is at the forward most location within the dynamic boundary.

FIG. 3 provides a graph 300 showing the range of allowable vehiclespeeds within a dynamic boundary. The graph 300 includes a Y-axisindicating increasing vehicle velocities and an X-axis indicatingmovement of the vehicle along the direction of travel of the ride path.On the X-axis, the dynamic boundary length, 320 is demarcated between anX-location associated with the rear or back boundary of the dynamicboundary at 322 and an X-location associated with the front boundary ofthe dynamic boundary at 324. The designations “front” and “back” areprovided to assist discussion and understanding as the dynamicboundaries can be designated sides, top, bottom, or other referencedesignation. On the Y-axis, the range of allowable vehicle speeds 310 isshown between a maximum speed 330 and a minimum speed 338, with thenominal speed 334 between these two limiting values.

The line 350 shows that a vehicle at the back or rear edge 322 of thedynamic boundary may travel at any speed in the range 310 up to themaximum value 330 until the controller determines the vehicle isapproaching the front or leading edge 324 at which point the controllergoverns the speed of the vehicle down to the nominal vehicle speed 334(i.e., the speed of the dynamic boundary in which the vehicle isconstrained). The graph 300 also shows with line 355 that a vehiclestarting at the front or leading edge 324 may travel at any rate in therange 310 down to the minimum speed 338 until the controller determinesthe vehicle is at or quickly approaching the second or trailing edge 322of the dynamic boundary. At this point, the controller governs thevehicle's propulsion mechanism to speed up to at least the nominal speed334 to remain within the dynamic boundary by traveling at least as fastas the dynamic boundary along the ride path in the direction of travelof the dynamic boundary.

One technique for defining a dynamic boundary size for managingprogression of vehicles in the ride 100 of FIGS. 1 and 2 involvesdetermining that it is desirable to have a ride throughput capacity of1000 riders or passengers per hour for a ride with vehicles that havecapacities of 4 passengers per vehicle. This may lead to a determinationthat the nominal vehicle speed (and dynamic boundary speed) should be 6feet per second along the ride path. Other known parameters may includea vehicle length of 8 feet, a braking deceleration rate of 8 feet persecond squared and a response time of 0.25 seconds for control signals.With this information, a dispatch interval of 14.4 seconds, a nominalspacing of 86.4 feet, and a stopping distance of 3.75 feet all can bedetermined, and the calculated or predefined dynamic boundary length maybe set at 74.65 feet for a ride with these design and/or operatingparameters. If these parameters are changed, the dynamic boundary lengthprobably will also change. The dynamic boundary length is often not keptat a fixed value through the length of the ride path (or track) and maybe varied to achieve particular control goals or needs.

FIGS. 4A and 4B illustrate a portion of a ride configured to controlvehicle progression within dynamic boundaries or envelopes. FIG. 4Ashows dynamic boundaries 410, 412, 414, 420 moving as shown with arrow440 at a speed or progression rate in a direction of travel. FIG. 4Ashows the chain or train of dynamic boundaries 410, 412, 414, 420 at afirst time, “T.” As the dynamic boundary progression 440 occurs, avehicle 430 is contained in the dynamic boundary 420 (and other vehiclesare in dynamic boundaries 410, 412, 414). The dynamic boundary 420, forexample, defines a space or movement region within boundaries providedby trailing edge 422, leading edge 424, right (lower) edge 426, and left(upper) edge 428. The vehicle 430 may be controlled by a controller (notshown in FIG. 4) to respond to rider input via an input device on thevehicle 430 to move as shown with arrow 435 in two or moredimensions/directions (e.g., in the X and/or Y directions (e.g.,sideways) or along/away from the direction of travel of the dynamicboundary 420 and/or transverse to the direction of travel of the dynamicboundary 420 along the ride path).

Often, the vehicle 430 may move at any speed within an acceptable range(as discussed with reference to FIG. 3) and in any direction until thelocation of the vehicle 430 would cause the vehicle 430 (or any portionof its exterior with or without a safety envelope placed around thevehicle) to contact a boundary edge/line 422, 424, 426, or 428. At thispoint, the controller typically would require the vehicle 430 to travelat the nominal speed in the direction of travel of the dynamic boundary420 along the ride path (or even cause the vehicle to move back toward amore central location or a default location).

In FIG. 4B, the ride 400 is at a second, later time, “T+dT,” in whichthe dynamic boundaries 410, 412, 414, 420 have progressed some distancealong the ride path due to movement indicated by arrow 440 (e.g.,dynamic boundaries move at the nominal speed as discussed with referenceto FIG. 3 from the time shown in FIG. 4A to the time shown in FIG. 4B).As suggested by arrows 435, vehicle 430 moves within the dynamicboundary 420 such that it is in a second location relative to theboundaries of the dynamic boundary 420 that differs from the firstlocation relative to the boundaries of the dynamic boundary 420 shown inFIG. 4A. Rider input may have been provided that cause the vehicle 430to move a transverse direction and also to move rearward in the dynamicboundary 420 toward the trailing edge or boundary line 422 (e.g., tomove slower than the nominal speed of dynamic boundary 420 in theelapsed time between the first and second times of FIGS. 4A and 4B).

FIG. 5 illustrates a portion of a ride system 500 similar to those shownin FIGS. 1, 2, 4A, and 4B but that is designed to include an obstacle538 in the ride path. The ride 500 is controlled such that a vehicle 512is able to move in multiple directions as suggested by arrows 513.Movement of vehicle 512 may be based on rider input and/or be based on acontrol module/program, and these movements are constrained to be withinthe space defined by the boundaries (size and shape) of the dynamicboundary 510. The dynamic boundary 510 progresses along the ride path atthe nominal speed defined for the particular portion of ride 500 andapproaches the obstacle 538. As shown, a dynamic boundary 530 initiallycontacting the front edge/side of the obstacle 538 is configured tosplit with a first portion or defined space moving 520 along one side ofthe obstacle 538 as shown by arrow 520 and a second portion or definedspace moving along a second or opposite side of the obstacle 538 asindicated by arrow 524. A vehicle 532 in the dynamic boundary 530 maymove based on rider input (or control program input such as randomselection or every other vehicle) to follow one of the dynamic boundaryprogressions/paths 520 or 524 and will move into one of the splittingregions as it is restrained within the dynamic boundary boundaries 534.

As shown, the vehicle 542 leading the vehicle 532 has moved into thelower region such that it is in a lower one of the split dynamicboundaries 541 while the upper one of the split dynamic boundaries 540is empty (contains no vehicle, contains another vehicle that has itsdynamic boundary dynamically increased in size to take advantage of theavailable space, or may not exist in some control applications). Thevehicle 552 leading the vehicle 542 took the upper passage and is in anupper one of a pair of split dynamic boundaries 550, 551 as it travelsaround the obstacle 538. The split dynamic boundaries 540, 541, 550, 551may be any size and shape and do not need to be the same as upstreamdynamic boundaries 510 to suit the obstacle or ride designer's needs.Downstream of the obstacle 538, pairs of split dynamic boundaries 550and 551 may join to form a single dynamic boundary 560 and as indicatedby boundary flow or progression paths 568, 569 and shown to containvehicle 562. The vehicles enter a downstream dynamic boundary as shownfor vehicle 572 in dynamic boundary 570 that may have the shape and sizeof the upstream dynamic boundary 510 as shown or be of a different shapeand size. FIG. 5 shows that the dynamic boundaries used to controlvehicles may split and merge around one or more branching elements (suchas obstruction 538) and also that the dynamic boundaries may be variedin size and shape along the ride path, which will further limit vehiclemovement or further free the vehicle for more movement.

FIG. 6 illustrates a portion of a ride system 600 illustrating dynamicboundaries of changing size and shape to constrain vehicles to provideprecise planned movements (i.e., to reduce or even eliminate freedom ofmovement based on rider input by collapsing the dynamic boundaryboundaries down to about the size of the vehicle). As shown, the ride600 includes a first set of dynamic boundaries such as dynamic boundary610 with a first relatively long length, L_(CB1), and the vehicle 612 isfree to move in either direction into boundary portions 613 within thedynamic boundary 610 between the ends 614, 616 defining the length,L_(CB1). The vehicle 612 may be 6 to 10 feet in length and the dynamicboundary length, L_(CB1) may be 20 to 50 feet providing significantfreedom of movement for the vehicle 612 within the dynamic boundary 610as it progresses along the ride path as indicated by arrow 618.

As the vehicles approach a portion of the ride 600 where tighter controlover vehicle movement is desired, a smaller or collapsed dynamicboundary 620 is used to constrain vehicle 622 and its movements withinboundaries/edges 624, 626. The smaller dynamic boundary 620 at a secondlocation in the ride 600 has a second dynamic boundary length, L_(CB2),that is less than L_(CB1) to reduce movement as shown with arrow 623 ofvehicle 622, e.g., in the above example, the length may be shrunk from40 to 50 feet to 20 to 30 feet or the like. Then, when even tightercontrol is desired, a dynamic boundary 630 may further constrain avehicle 632 such that its movement as shown with arrow 633 between ends634, 636 is tightly limited (i.e., the third dynamic boundary length,L_(CB3), is only a small amount larger than the vehicle length) ornonexistent (i.e., the third dynamic boundary length, L_(CB3), is thesame as or substantially the same as the length of the vehicle). In thismanner, dynamic boundaries that vary in size and shape over the lengthof the ride path can readily provide significant amounts of movement orfreedom within the dynamic boundary or provide much smaller or nofreedom of vehicle movement such that the vehicle progresses with thevehicle's dynamic boundary (i.e., the nominal speed of the ride or thedynamic boundary velocity or progression rate) along the ride path.

FIG. 7 illustrates yet another portion of a ride system 700 similar tothose of FIGS. 1, 2, and 4A-6 that is adapted to show dynamic boundariesmay force a vehicle to travel through a restriction in the ride pathsuch as to pass through a gate, door, or hole in a wall (or otherfeature). As shown, the ride system 700 includes a wall or otherobstruction 780 with a hole or opening 784. The ride system 700 isconfigured to first control progression of a vehicle 712 with a dynamicboundary 710 with a width, W_(CB1), that is much greater than the widthof the hole/opening 784 in the obstruction or feature 780 such that thevehicle 712 has significant range of movement transverse to thedirection of travel (and in the direction of such travel). The dynamicboundary 710 is moved at a nominal speed as shown with arrow 720 towardthe obstruction or feature 780 where if nothing was changed in thecontrol method the vehicle 712 could collide with the obstruction 780.

Instead, the control within the ride system 700 acts to provide adynamic boundary 730 at the location of the obstruction 780 that necksdown in width to a second width, W_(CB2), at the location of theobstruction 780. The width, W_(CB2), may be the same as or some amountless than the width of the opening 784 and be at the location of theopening 784 such that the dynamic boundary 730 has a boundary thatpasses through the opening 784 and does not include the obstruction 780.In this manner, the vehicle 732 may move as shown with arrow 734 in anydirection including transverse to the direction of travel in the dynamicboundary 730 except its movement is directed through the hole 784, e.g.,the transverse movement is restricted when the vehicle 732 is determinedby the dimensions and shape of the boundary of the dynamic boundary 730to be approaching and then passing through the hole 784.

FIG. 8 illustrates a ride portion 800 configured to provide control ofvehicles when the ride path has an intersection/crossing. This can beachieved using dynamic boundaries that are configured to force spacingof the vehicles for path crossings. As shown, the ride portion 800includes a first set 810 of dynamic boundaries each containing a vehicleand a second set 820 of dynamic boundaries each containing a vehicle,and the two sets 810, 820 have crossing ride paths. The controller (notshown) of ride portion 800 is adapted to use dynamic boundaries 830, 831approaching the crossing/intersection to constrain vehicles 832, 833within a first, relatively large length, L_(CB1).

These first dynamic boundaries 830, 831 in each set 810, 820 progress inthe directions indicated by arrows 811, 821 toward the crossing and arespaced apart by a first spacing, S₁, from a next dynamic boundary 840,841 used to constrain movement of vehicles 842, 843. This first spacingis relatively small as the distance is provided in dynamic boundaries830, 831. The length of the dynamic boundaries shrinks, though, as seenfor the length, L_(CB2), of the second pair of dynamic boundaries 840,841 approaching the intersection of the two ride paths. This shrinkingallows a larger spacing, S₂, between a dynamic boundary with an evensmaller length, L_(CB3), passing as shown with arrow 821 through thecrossing/intersection. Once the dynamic boundaries 850, 851 pass throughthe intersection/crossing, they may be returned to or stretched back tothe first (or second or another) length, L_(CB1), that is longer thatthe crossing length, L_(CB3), and the spacing may be returned to thefirst spacing or shrunk further as shown at S₃ (provide to the dynamicboundaries 850, 851 movement of vehicles such as vehicle 852 in dynamicboundary 850). Hence, the control method may be thought of as reducinglengths of dynamic boundaries near an intersection to limit vehiclemovement into dynamic boundary spacing between adjacent dynamicboundaries to eliminate the risk of a collision at a path crossing.

FIG. 9 illustrates a functional block diagram of a ride system 900according to the present description. The ride system 900 is adapted forutilizing the logical construct of dynamic boundaries for managingprogression of passenger vehicles, adapted for rider input on movement,through a ride (along a ride path). The system 900 is shown to includethe hardware, data files, and software/algorithms that may perform thefunctions described herein, and each of these components is identifiedas shown by the key of FIG. 9.

It will be understood that the hardware and algorithm items may beimplemented with any combination of hardware, firmware, and software(e.g., a hardware item may include software or be replaced by softwareor vice versa). Also, one or more computers or computing devicesconfigured for the special purpose of providing these functions mayexecute the software or algorithms (code or instructions executable bythe computers/computing devices) to provide the “controllers” of thepresent description. Still further, although not shown, the data fileswill be saved in non-transitory medium or data storage (as would be theexecutable code) at least periodically and would be communicated amongthe hardware and software components in a wired or wireless manner (asis known or as developed after the writing of this description).

The ride system 900 controls a plurality of passenger vehicles thattravel along a ride path. With this in mind, components of a singlevehicle are shown for illustration, and these components would beprovided in each vehicle. Particularly, in the system 900 each passengervehicle would include a vehicle drive (or motion) assembly 910 thatincludes one or more vehicle propulsion drives 912 (to set the velocityor speed of the vehicle along the ride path), a vehicle steeringassembly 914 (to control the direction of travel of the vehicle relativeto the ride path such as along the path or transverse to such a path insome applications such as a FRV ride), and one or more vehicle rotationdrives 916 (to allow the vehicle body to spin or rotate about an axis toorient the front of the vehicle relative to the ride path or directionof travel). During operation of the ride system 900, the controller orcontrol components (such as a state change limiter module 970) may actto transmit or communicate vehicle control commands 918 to the vehicledrive/motion assembly 910 to manage progression and operation of thevehicle as it moves within a dynamic boundary, which is progressing at anominal or settable rate along a ride path.

The vehicle may also include driver input(s) 930 such as received viaoperation of a steering wheel, joystick, a touchscreen, acceleratorpedal, brake pedal, and the like. These may be operated by a rider orpassenger of the vehicle to control or affect movement of their vehiclealong the ride path, and the ride system 900 is configured tocommunicate these (or a portion of these) inputs as shown at 931 to aportion of the controller. Particularly, software module 934 is providedthat is executed to decompose or process the received driver inputs 931to determine the rider's desired change for the vehicle's operatingstate.

The driver may press the accelerator or the brake, and the module 934may act to determine a delta speed value (e.g., increase or decreasevehicle speed by an amount). In other cases, the driver inputs 930 maybe used by the rider to change the position of the vehicle within thedynamic boundary such as by turning a steering wheel or moving ajoystick to the left or right, and the module 934 may determine a deltaposition value (e.g., move to the left or right relative to the presentdirection of travel in the dynamic boundary). In other cases, the driverinputs 930 may include input to rotate the vehicle to change itsorientation, and the module 934 may act to determine a delta orientationvalue (spin clockwise or counterclockwise). The result may include themodule 934 acting to transmit a desired vehicle state change 936 to thestate change limiter 970 for a determination whether such change instate is allowable, and, if so, transmitting a vehicle control command918 to the appropriate component of the drive assembly 910 (e.g., to thevehicle propulsion drive 912 when the state change requested is toaccelerate or decelerate).

Module 970 is configured to process the desired vehicle state change 936to insure that the vehicle remains within the dynamic boundaryconstraints (e.g., cannot go slower than the dynamic boundary's nominalspeed when at the trailing or second boundary of the dynamic boundary).To make this determination, the state change limiter 970 takes a currentvehicle state 924 as input from one or more vehicle state sensors 920.The sensors 920 may be onboard and/or off board the vehicle and maycollect data, which may be stored at least temporally in memory,including a present vehicle speed (and direction of movement), aposition of the vehicle (e.g., which can determine the relative positionof the vehicle to the present boundaries of the dynamic boundary andtheir locations as the dynamic boundary moves along the ride path), anda vehicle orientation (e.g., which can determine the direction the riderwants vehicle to move in dynamic boundary).

The limiter 970 also takes an allowable vehicle state 964 as input. Thelimiter 970 acts to compare the current vehicle state 924 with theallowable vehicle state 964 to determine whether the desired vehiclestate change 936 can be implemented or used to affect the vehicle stateto remain within the dynamic boundary constraints. The results arevehicle control commands 918 provided to the vehicle drive assembly 910,e.g., force vehicle to be steered in a first direction to follow a ridepath and remain in dynamic boundary rather than implementing statechange 936 that would have moved vehicle out of the dynamic boundary orslow vehicle down to a speed slower than the dynamic boundary's nominalspeed causing the vehicle to move toward the rear boundary or the like.

The allowable vehicle state 964 is generated by a software module 960that functions to provide interpolation of profile data 940 to determinean allowable vehicle state, which may define the allowable range ofvehicle speeds, the allowable vehicle positions, and the allowablevehicle orientation relative to the direction of travel along a ridepath. The interpolation may be performed by the module 960 based on apresent time 956 provided by a progression time reference 950, as thelocation and present state (size and shape) of each of the dynamicboundaries along a ride path may be determined based on a dispatch time,predefined nominal speed for the vehicles/dynamic boundaries, andpresent time 956. The profile data 940 may be set by data indicating alocation for each dynamic boundary relative to time as shown at 944 andby data indicating the constraints for the vehicle relative to time asshown at 946 (e.g., the speed, position, and orientation of the vehiclewithin the dynamic boundary may be set based on time from dispatchrather than merely on the boundaries of the dynamic boundary and thevehicle's relative location to these boundaries). Further, the profiledata 940 may include the dynamic boundary profile 942, which may alsochange based on the time (or position along the ride path) such as tohave a shape and size at a first time while in the station, have agreater size after leaving the station, another profile to allow avehicle to go around an obstruction, through an opening in anobstruction, to safely pass through a path crossing, and/or to force avehicle to have a position relative to a show feature along the ridepath.

The controller or control methodology described using dynamicboundaries, and shown as it may be implemented in FIG. 9, may beimplemented by managing progression within the vehicle or with an offboard controller. FIG. 10 shows the system 900 as it may be implementedas a vehicle-managed dynamic boundaries system 1000. As shown, an offboard computer or controller 1020 may provide start and stop commands1022 to initiate and halt ride operations. A vehicle or onboardcontroller or computer 1010 is on the vehicle. The vehicle controlcommands 918 are generated by the onboard controller/vehicle computer1010, which would be adapted to run the modules 934, 960, 970 and memory(or access to memory) storing the data files 942, 944, 946.

In other cases, though, it may be desirable to provide a centralcontroller or off board managed dynamic boundaries, and the system 1100implements the system 900 in this manner as shown in FIG. 11. In thissystem 1100, the vehicle computer/controller 1110 is adapted to run therider input processing module 934 and the state change limiter module970 to generate the control commands 918. However, the allowable vehiclestate 1128 and start/stop commands 1122 are generated by an off boardcomputer/controller 1120. The controller 1120 is configured to have thememory (or access to such memory) that stores the data files 942, 944,946 and also to execute code or instructions for the module 960 toprovide interpolation of this data and the reference time 956 to createthe allowable vehicle state 1128.

Although the invention has been described and illustrated with a certaindegree of particularity, the particular implementations described in thepresent disclosure has been as examples, and numerous changes in thecombination and arrangement of parts can be resorted to by those skilledin the art without departing from the spirit and scope of the invention,as claimed. The dynamic boundaries shown were often isolated from eachother, but it will readily be understood that other embodiments mayinclude dynamic boundaries within dynamic boundaries. In this manner, adynamic boundary may manage progress of a set of smaller dynamicboundaries and their corresponding vehicles. Further, the dynamicboundaries shown were often shown to include one passenger vehicle, butother embodiments may include two or more vehicles with vehiclecollisions allowed or managed/controlled in other ways.

We claim:
 1. A method of controlling vehicle progression along a ridepath of an amusement park ride, comprising: receiving inputs from inputdevices operable by a passenger of a vehicle on the ride path;processing the received inputs to determine a vehicle state change;determining a vehicle state; comparing the vehicle state with a set ofconstraints defined by a dynamic boundary associated with the vehicle;and based on the comparing step and the vehicle state change, issuingvehicle control commands to a drive assembly of the vehicle to implementthe vehicle state change, whereby the vehicle complies with the set ofconstraints.
 2. The method of claim 1, wherein the dynamic boundarymoves along the ride path at a nominal speed during operating of theamusement park ride and wherein the dynamic boundary defines a set ofboundaries for the vehicle.
 3. The method of claim 2, wherein thevehicle state change comprises a change in the vehicle speed and whereinthe issuing vehicle control commands causes the vehicle to travel at aspeed differing from the nominal speed of the dynamic boundary.
 4. Themethod of claim 3, wherein the speed of the vehicle is governed to forcethe vehicle to remain within the set of boundaries.
 5. The method ofclaim 2, wherein the vehicle state change comprises a transversemovement relative to a direction of travel of the dynamic boundary alongthe ride path.
 6. The method of claim 2, wherein the set of boundariesdefine a dynamic boundary length as measured between a leading end ofthe dynamic boundary and a trailing end of the dynamic boundary andwherein the length is greater than a length of the vehicle at least forportions of the ride path.
 7. The method of claim 2, wherein the lengthof the dynamic boundary is modified from a first length in a firstportion of the ride path to a second length greater than the firstlength during a second portion of the ride path.
 8. The method of claim2, wherein the set of boundaries define a dynamic boundary width andwherein the width is varied along the ride path, whereby an amount oftransverse movement of the vehicle is controlled to direct the vehiclethrough openings in obstructions.
 9. An amusement park ride, comprising:a ride path; a plurality of passenger vehicles each adapted with aninput device operable by a passenger; and a controller comprising memorystoring a profile for a dynamic boundary for each of the passengervehicles and a processor executing code causing the processor todetermine for each of the passenger vehicles an allowable vehicle statebased on the control based on the dynamic boundary profile, to processinputs from the input device to determine a passenger-desired vehiclestate change, and to issue vehicle control commands to control operationof the passenger vehicle by processing the passenger-desired vehiclestate change to comply with the allowable vehicle state.
 10. The systemof claim 9, wherein the allowable vehicle state comprises a range ofpositions within a boundary defined by the dynamic boundary profile 11.The system of claim 10, wherein the vehicle control commands are adaptedto provide movement from a current position within the dynamic boundaryto a new position within the boundary.
 12. The system of claim 11,wherein the boundary defined by the dynamic boundary profile varies insize and shape along the ride path.
 13. The system of claim 9, whereinthe passenger-desired vehicle state change comprises a change in speedof the vehicle along the ride path and wherein the vehicle controlcommands affect control over a vehicle propulsion drive to cause a speedof the vehicle to be increased or decreased from a current speed whileretaining the vehicle within a logical boundary for the passengervehicle along the ride path.
 14. The system of claim 13, wherein thedynamic boundary profile defines a range of allowable vehicle speeds forthe passenger vehicle based on a current location of the passengervehicle within the logical boundary and wherein the range of allowablevehicle speeds includes speeds greater than and less than a nominalspeed for the dynamic boundary over the ride path.
 15. A control methodfor managing vehicle movements, comprising: for each vehicle of a ride,providing a dynamic boundary defining a spatial boundary for movement ofeach the vehicles relative to a ride path; during operation of the ride,determining a current speed of one of the vehicles; processing inputfrom the one of the vehicles to modify speed; and based on a currentlocation of the one of the vehicles within the dynamic boundary providedfor the one of the vehicles, controlling a propulsion drive for the oneof the vehicles to adjust the current speed while retaining the one ofthe vehicles within the spatial boundary, wherein the spatial boundarydefined for each of the dynamic boundaries changes in length at two ormore locations along the ride path.
 16. The method of claim 15, whereinthe spatial boundaries defined for the dynamic boundaries are spacedapart along the ride path.
 17. The method of claim 15, wherein thespatial boundary defined for each of the dynamic boundaries changes inwidth at two or more locations along the ride path.
 18. The method ofclaim 15, further comprising moving the dynamic boundaries along theride path at a nominal speed, whereby the spatial boundary for each ofthe vehicles moves over time along the ride path.
 19. The method ofclaim 18, wherein the current speed is greater than or less than thenominal speed.
 20. The method of claim 18, further comprising processinginput from the one of the vehicles to move transverse to a direction oftravel of the dynamic boundary provided for the one of the vehicles andcontrolling vehicle steering to move the one of the vehicles transverseto the direction of travel while remaining within the spatial boundaryof the dynamic boundary provided for the one of the vehicles.